Tiltable work platform

ABSTRACT

A work platform assembly  10  of the invention has a base  12  and a work platform  36  movable with respect to the base  12 . The work platform  36  can be connected to the base  12  by at least one pivot arm. A lift device  64  is configured to move, e.g., raise and tilt, the work platform  36  with respect to the base  12 . In one particular embodiment, the work platform  36  is connected to the base  12  by a plurality of pivot arms that are pivotally connected to the base  12  and the work platform  36 . In one embodiment, the lift device  64  is a pneumatic lift bag located between the base  12  and the work platform  36 .

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefits of U.S. Provisional ApplicationSer. No. 60/524,100, filed Nov. 21, 2003, and is related to U.S. patentapplication Ser. No. 10/349,503, filed Jan. 22, 2003, which claimspriority to U.S. Provisional Application Ser. No. 60/351,492, filed Jan.24, 2002, all of which applications are herein incorporated by referencein their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to industrial work platforms and, moreparticularly, to a work platform assembly having a tiltable workplatform.

2. Description of the Currently Available Technology

In many industrial applications, manufacturing components, such as partsfor use on an assembly line, are packed in large shipping containers andshipped from one location to another, such as from a manufacturer to anassembly facility. Typically, the parts are placed in layers in theshipping container with the layers separated by packing material. Theshipping container is moved to a workstation at the assembly facilitywhere the parts are unpacked and used by a worker on an assembly line.This movement is typically done using a conventional motorized vehicle,such as a forklift truck. At the workstation, the container is typicallyremoved from the vehicle and placed on the floor. The container isopened and the top packing layer is removed to expose the top layer ofparts. This top layer of parts can then be removed from the shippingcontainer until all of the parts in this layer are gone. The next layerof packing material can then be removed to expose the underlying layerof parts and these parts can also be removed. Depending upon the size ofthe parts and the size of the shipping container, several layers ofparts can be packed in one container.

One drawback of this system is that as the upper layers of parts areremoved, the remaining layers of parts become more and more inaccessiblesince they are lower in the container. If the container is simply placedon the floor near the workstation, the worker removing the parts mustbend lower and lower to access and remove each successive layer ofparts. Further, as the layers of parts are removed, the lower layers ofparts on the side of the container opposite to where the worker isstanding may be beyond the reach of the worker. Therefore, the workermay have to walk around the container to get the parts on the otherside. This consumes valuable time which could be more productively usedin the actual manufacturing or assembly process.

In order to reduce this problem, tiltable work platforms have beendeveloped. These conventional work platforms typically have a lift tablewith a lifting device configured to elevate the lift table and a tilttable with a separate tilting device configured to tilt the tilt tablewith respect to the lift table. While these conventional systems workwell, there are some drawbacks. For example, the use of separate liftand tilt tables, as well as separate lifting and tilting devices,increases the mechanical complexity and manufacturing costs for thesedevices.

Therefore, it would be advantageous to provide an apparatus and/ormethod of improving the access of a worker to the open container at aworkstation that reduces or eliminates at least some of the problemsassociates with conventional systems. It would also be desirable toprovide a work platform assembly that provides a more ergonomicallyadvantageous positioning of a container utilizing a less mechanicallycomplex apparatus than is currently utilized.

SUMMARY OF THE INVENTION

A work platform assembly of the invention comprises a base and a workplatform movable with respect to the base. The platform can be connectedto the base by at least one pivot arm. A lift device is configured tomove, e.g., tilt and/or raise, the platform with respect to the base.

In one particular embodiment, the platform is connected to the base by aplurality, e.g., four, pivot arms that are pivotally connected to thebase and the platform. For example, a forward or first set of pivot armsand a second or rear set of pivot arms can be connected to the base andplatform. The lift device can be any device configured to move, elevate,and/or tilt the platform with respect to the base. In one embodiment,the lift device comprises a pneumatic lift bag located between the baseand the platform.

BRIEF DESCRIPTION OF THE DRAWINGS

The general concepts of the invention will be described with referenceto the following drawing figures wherein like reference numbers identifylike parts throughout.

FIG. 1 is a side view of a work platform assembly of the invention in alowered position;

FIG. 2 is a perspective view of the work platform assembly of FIG. 1;

FIG. 3 is a perspective view of the work platform assembly of FIG. 2 inan elevated position;

FIG. 4 is a side view of the work platform assembly of FIG. 3 showingthe position of a carton on the platform;

FIGS. 5 and 6 are top and bottom views, respectively, of the workplatform assembly of FIG. 1; and

FIGS. 7 and 8 are side views of the work platform assembly of FIG. 4showing various dimensions of a particularly preferred embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used herein, spatial or directional terms, such as “top”, “bottom”,“left”, “right”, “up”, “down”, “front”, “rear”, and the like, relate tothe invention as it is shown in the drawing figures. However, it is tobe understood that the invention can assume various alternativeorientations and, accordingly, such terms are not to be considered aslimiting. Further, all numbers expressing dimensions, physicalcharacteristics, and so forth, used in the specification and claims areto be understood as being modified in all instances by the term “about”.Accordingly, unless indicated to the contrary, the numerical values setforth in the following specification and claims can vary depending uponthe desired properties sought to be obtained by the present invention.At the very least, and not as an attempt to limit the application of thedoctrine of equivalents to the scope of the claims, each numericalparameter should at least be construed in light of the number ofreported significant digits and by applying ordinary roundingtechniques. Moreover, all ranges disclosed herein are to be understoodto encompass any and all subranges subsumed therein. For example, astated range of “1 to 10” should be considered to include any and allsubranges between (and inclusive of) the minimum value of 1 and themaximum value of 10; that is, all subranges beginning with a minimumvalue of 1 or more and ending with a maximum value of 10 or less, e.g.,5.5 to 10. The dimensions shown on the attached drawings represent oneembodiment of the invention and should not be considered as limiting.

An exemplary work platform assembly of the invention will first bedescribed and then a method of utilizing the work platform assembly toretrieve parts from a shipping carton will be described. However, it isto be understood that the exemplary work platform assembly described inthe following discussion and specifically shown in the drawings ispresented simply to disclose the general concepts of the invention andthe invention is not limited to the specifically disclosed embodiment.

As shown in FIGS. 1-4, an exemplary work platform assembly 10 of theinvention includes a base 12. In the illustrated exemplary embodiment,the base 12 includes a flat bottom 14 with a left side wall 16, a rightside wall 18, a front wall 20, and a rear wall 22 each extendingupwardly from the bottom 14. As shown particularly in FIG. 3, an innerleft side wall 24 can be located inwardly from the left side wall 16 toform a slot or space 26 between the inner left side wall 24 and theouter left side wall 16. Similarly, an inner right side wall 28 can bespaced inwardly from the outer right side wall 18 to form a slot orspace 30 between the inner right side wall 28 and outer right side wall18. The base components can be made of any suitable material, such asbut not limited to metal, and can be of any desired dimensions.

A work platform 36 is movable relative to the base 12. In theillustrated embodiment, the work platform 36 includes a flat top 38having a front 40 and a rear 42. A stop 44 is attached to the front 40of the work platform 36. In the disclosed embodiment, the stop 44 can bea metal plate extending upwardly from the front 40 of the work platform36. The work platform 36 can be of any desired material, such as but notlimited to metal, and can be of any desired dimensions.

The work platform assembly 10 includes means for tilting and/orelevating the work platform 36 with respect to the base 12. In the broadpractice of the invention, any conventional tilting means can beutilized, such as scissors mechanisms, hydraulic devices, hingeassemblies, one or more pivot arms, and the like. For example, the workplatform assembly 10 can include one or more supports extending betweenand pivotally connected to the base 12 and the work platform 36. In theillustrated embodiment, the work platform assembly 10 includes a firstforward support 50 spaced from a second forward support 52. In theillustrated embodiment, the forward supports 50, 52 can be metal stripsor arms, with one end of each arm pivotally connected to the base 12 andthe other end of each arm pivotally connected to the work platform 36.As shown particularly in FIG. 3, the forward supports 50, 52 can beattached to the base 12 between the inner and outer side walls, i.e.,can pivot in the spaces 26, 30 between the inner and outer side walls.The upper end of each support 50, 52 is attached to the work platform36, e.g., near the front 40 of the work platform 36.

The work platform assembly 10 can further include at least one rearsupport, such as at least one pivotable metal arm. In the illustratedembodiment, a first rear support 56 is spaced from a second rear support(not shown in the figures). The upper ends of the rear supports arepivotally connected to the work platform 36, e.g., at a position spacedfrom the upper ends of the forward supports 50, 52. The upper ends ofthe rear supports are connected to the work platform 36 rearwardly ofthe upper ends of the forward supports 50, 52. The lower ends of therear supports are pivotally connected to the base 12. The rear supportscan form or can be connected to a receiver 60 configured to receive oneend, e.g., the upper end, of a lift device as described in more detailbelow. In the illustrated embodiment, the receiver 60 (FIG. 4) is asubstantially inverted U-shaped (in cross section) member locatedbetween the rear supports. For example, the receiver 60 can be locatedon or formed in a metal piece extending between the rear supports.

A lift device 64 is positioned between the base 12 and the work platform36 and is configured to elevate, tilt, or move the work platform 36 withrespect to the base 12. The lift device 64 can be of any conventionaltype, such as but not limited to a mechanical screw, a scissors-typelifting mechanism, a hydraulic jack, an electrical lifting arm, or apneumatic lift device, just to name a few. In the illustratedembodiment, the lift device 64 is a pneumatic device comprising one ormore conventional lifting bags 66 which, when inflated, lift, tilt,and/or elevate the work platform 36 with respect to the base 12.Suitable lifting bags are commercially available from Carter Lift Bag,Inc. of Enumclaw, Wash. In the illustrated embodiment, the bottom of thelift device 64 is attached to or rests on the base 12. The top of thelift device 64 is connected to at least one of the rear supports. Forexample, the top of the lift device 64 can extend into the receiver 60,e.g., when inflated. The lift bag can be, for example, a wedge-shapedlift bag. By “wedge-shaped lift bag” is meant a lift bag that, wheninflated, forms a wedge shape such that the top surface of the lift bagis inclined or angled with respect to the lift bag bottom. In anotherembodiment, the receiver 60 can be connected to or formed on the bottomof the work platform 36 rather than connected to the rear supports.

An exemplary method of utilizing the work platform assembly 10 of theinvention will now be described. As shown in FIGS. 1 and 2, with thework platform assembly 10 in the lowered position, the front or upperends of the front and rear supports are pivoted forward with respect tothe base 12, and the bottom 14 of the work platform 36 rests on or isadjacent to the top of the base 12 (i.e., the upstanding walls of thebase 12). As shown in FIGS. 4, 7, and 8, a carton 70 containing parts tobe unloaded can be placed on top of the work platform 36 with the frontof the carton 70 adjacent to or abutting the inner surface of the stop44. To elevate the work platform 36 and provide access to the contentsof the carton 70, the lift device 64 is activated. As will be understoodparticularly from FIGS. 4 and 7, as air is introduced into the pneumaticlift device, the lift device 64 pushes or applies a pressure upwardlyagainst the rear supports, e.g., into the receiver 60. As the liftdevice 64 pushes upwardly against the receiver 60 (or rear supports),the work platform 36 is pivoted upwardly on the front and rear supports,with the front of the work platform 36 moving in the path 72 and therear of the work platform 36 moving in the path 73 shown in dashed linesin FIG. 7. When the work platform 36 reaches a desired elevation and/orangle, the lift device 64 can be stopped to hold the work platform 36 atthe desired elevation and/or angle. The stop 44 prevents the carton 70from sliding off the front of the work platform 36. The work platform 36can be held in place by the pressure of the lift bag, or a conventionallocking device, such as a metal rod or metal latch, can be used to holdthe work platform 36 in place.

As will be appreciated by one skilled in the art, the work platformassembly 10 of the invention provides both a lifting and tiltingfunction without the need for separate lift and tilt tables nor the needfor separate lifting and tilting devices. The present invention combinesboth the lifting and tilting functions into one simple mechanicaldesign. The lifting and tilting functions occur in one continuous orprogressive motion rather than in two separate stages, as with previouswork platforms.

As shown by lines 72 and 73 in FIG. 7, the work platform 36 initiallybegins to lift when the lifting device is activated and then smoothlylifts and tilts until a final desired position is achieved. A majorityof the tilting motion occurs near the end of the lifting motion.

Most shipping cartons have drop doors 74 which fold down to allow easieraccess to parts at the bottom of the carton. A worker can begin toremove parts from the carton 70 and, when the level of parts is belowthe level of the drop door 74, can open the drop door 74 as shown inFIGS. 7 and 8 to allow the worker easier access to the parts near thebottom of the carton 70. When the required parts have been removed, thelocking device (if present) can be unlocked and the lift device 64 canbe deactivated or reversed to pivot the work platform 36 downwardlytowards the base 12 on the support arms. The carton 70 can then beremoved and another carton placed on the top of the work platform 36 andthe work platform 36 again elevated to allow the worker access to theparts in the container.

As shown particularly in FIG. 4, the present invention provides a moreergonomically advantageous positioning of a container than is possiblewith conventional devices. The container is positioned at a higherelevation, requiring less bending to access the parts, and also does notextend into the workstation as much as previous devices, which increasesthe work space available to a worker.

It will be readily appreciated by those skilled in the art thatmodifications may be made to the invention without departing from theconcepts disclosed in the foregoing description. For example, aturntable 80 (FIG. 4) could be attached to the bottom of the base 12 toallow the base 12 and, hence, the work platform assembly 10 to bepivoted or turned at the workstation. Accordingly, the particularembodiments described in detail herein are illustrative only and are notlimiting to the scope of the invention, which is to be given the fullbreadth of the appended claims and any and all equivalents thereof.

1. A work platform assembly, comprising: a base; a work platform movablewith respect to the base, wherein the platform is connected to the baseby at least one pivotable support; and at least one lift deviceconfigured to both lift and tilt the platform with respect to the base.2. The work platform assembly of claim 1, wherein the work platform isconnected to the base by at least one forward support and at least onerear support.
 3. The work platform assembly of claim 2, wherein theforward supports are connected at or near the front of the workplatform.
 4. The work platform assembly of claim 3, wherein the rearsupports are connected to the work platform rearwardly of the frontsupports.
 5. The work platform assembly of claim 1, wherein the liftdevice includes at least one pneumatic lifting bag.
 6. The work platformassembly of claim 1, including a turntable connected to the base.
 7. Thework platform assembly of claim 2, including a receiver operablyconnected to the at least one rear support and configured to engage thelift device.
 8. A work platform assembly, comprising: a base; a workplatform movable with respect to the base; a first forward supportspaced from a second forward support, with one end of each forwardsupport pivotally connected to the base and the other end of eachforward support pivotally connected near the front of the work platform;a first rear support spaced from a second rear support, with one end ofeach rear support pivotally connected to the base and the other end ofeach rear support pivotally connected to the work platform rearwardly ofthe front supports; and a pneumatic lifting device configured to liftand tilt the work platform with respect to the base.
 9. The workplatform assembly of claim 8, including a receiver operably connected tothe rear supports and configured to engage the lifting device.
 10. Thework platform assembly of claim 8, including a turntable connected tothe base.
 11. The work platform assembly of claim 8, including a stopconnected to the work platform.
 12. The work platform assembly of claim8, wherein the lifting device is a pneumatic lift bag.
 13. The workplatform assembly of claim 12, wherein the lift bag is a wedge-shapedlift bag.
 14. A work platform assembly, comprising: a base; a workplatform connected to the base by a pair of first supports spaced from apair of second supports, with one end of the first and second supportspivotally connected to the base and the other end of the first andsecond supports pivotally connected to the work platform; and apneumatic lift bag positioned between the base and the work platformsuch that inflation of the lift bag raises and tilts the work platformwith respect to the base.